Can a Seperate Battery Be Used to Power a Trailer Wiring Harness

Question:

If I wire the car but use a separate battery for the hitch wiring. Would this work, i can use a small battery in my RAV truck storage area.

asked by: Christopher

Expert Reply:

For starters, if you have a 2014 Toyota RAV4 then the correct trailer wiring harness for you is the Curt T-Connector Vehicle Wiring Harness part # C56350, not the Curt T-Connector Vehicle Wiring Harness part # C56033 which is a fit for Nissan and Infiniti models.

Regardless, the converter box really needs to be powered by the vehicle's battery but if you really wanted to install a separate battery in the truck area you can do so as long as it is rated for at least 10 amps. Please keep in mind that the separate battery in the truck would also require a charger which means you will need to run a power wire from the main battery to the separate battery which doesn't really make much sense.

If you need help routing the power wire for the wiring harness or separate battery I have attached a help article on this for you.

expert reply by: Conner L

Bryan C.

6/27/2020

I have 2018 Mercedes GLS 450 and the trailer hitch is installed, but no wiring harness. I just need to use for towing 4x9 u-haul triler when I get some 4x8 plywood, 2x4, and/or 2x6 etc. What would be the easiest way to wire and what wiring harness that I need to get? I think it is hard to route the power cable to the vehicle battery. Can I just use a separate 24V battery to connect the power cable?

Chris R.

7/1/2020

There aren't any custom harnesses available for your GLS-450 so you'll need to go with a universal hardwire kit. The Tekonsha # 119190KIT will work really well. If you wanted to add a dedicated 12V battery for the power wire you could, as long as you make sure to keep it fully charged and in good condition. Otherwise running the black wire up to the vehicle's battery is still the best route.